MLB to Experiment With Minor League Rule Changes on Shift Restrictions, Robo Umps

Major League Baseball will experiment with several rule changes at the minor league level, including an automated strike zone, larger bases and limits on defensive shifts.

Major League Baseball will experiment with several rule changes in the minor leagues this season, including an automated strike zone, restrictions on defensive positioning and larger bases.

The league said in a statement Friday the “changes being tested are designed to increase action on the basepaths, create more balls in play, improve the pace and length of games, and reduce player injuries.”

The league’s automatic ball-strike system will be used at some Low-A Southeast League games, the closest that computer umpires have come to the majors. ABS has already been used in the independent Atlantic League and the Arizona Fall League. It got mixed reviews from players, with complaints about how the TrackMan system grades breaking pitches down in the zone.

Infielders at Double-A will have to keep both feet in the infield at the start of every play. While a defensive team must have at least four players within the outer boundary of the infield dirt, there won’t be a ban on shifting three or more defenders to either side of second base, although the league may experiment with such a rule pending results of the initial experiment.

Triple-A is getting larger bases, expanding first, second and third from 15 by 15 inches to 18 by 18. MLB said it hopes to reduce player injuries and collisions, and also that the shortened distance between bases should “have a modest impact” increasing stolen baes and infield hits.

Pitchers at the lower levels will also be restricted in their ability to hold baserunners. At all High-A levels, pitchers will have to fully disengage from the rubber prior to throwing to a base under penalty of a balk. The rule will eliminate the most effective style of pickoff move used by left-handed pitchers — perhaps most effectively by Steve Carlton and Andy Pettitte.

In all Low-A leagues, pitchers will be limited to two step offs or pickoff attempts per plate appearance with at least one runner on base. Pitchers may attempt a third pickoff in the same plate appearance, but if the runner returns safely to his base, the pitcher will be charged with a balk. MLB says it will consider limiting pitchers to one step off or pickoff per plate appearance, pending the results of the initial experiment.

“We are listening to our fans,” said Michael Hill, MLB senior vice president of on-field operations. “This effort is an important step towards bringing to life rules changes aimed at creating more action and improving the pace of play.”

The Low-A West league will also adopt on-field timers previously used at other levels with additional regulations to reduce game length and improve pace of play.

The coronavirus pandemic wiped out the 2020 minor league season and is expected to delay the start of the 2021 schedule until around the first week of May. The minors were contracted from 160 teams to 120 this offseason following the expiration of the Professional Baseball Agreement governing the relationship between MLB and National Association of Professional Baseball Leagues, which operated the minors. MLB has since assumed full control of the enterprise.

“The game on the field is constantly evolving, and MLB must be thoughtful and intentional about progressing toward the very best version of baseball — a version that is true to its essence and has enough consistent action and athleticism on display to entertain fans of all ages,” said former Red Sox and Cubs executive Theo Epstein, now a consultant to MLB.

“These rules experiments will provide valuable insight into various ways to create a playing environment that encourages the most entertaining version of the game. What we learn in the Minor Leagues this year will be essential in helping all parties chart the right path forward for baseball.”

MLB also will continue its partnership with the Atlantic League and said it may announce additional rules experiments there in the coming weeks.